A structure for dispersing impact at a collision is conventionally adopted in a side part structure of a vehicle body in various vehicles, such as a passenger car. As this kind of side part structure of a vehicle body, there is known a combination structure of a center pillar in which the shape of a bulkhead is formed by an outer center pillar, and an inner panel of a side roof rail is sandwiched and combined in a sandwiched fashion by the outer center pillar and an inner center pillar (for example, refer to Patent Citation 1). Patent Citation 1: Japanese Unexamined Utility Model Registration Application Publication No. 63-119480.